The present invention relates to a polyamine which is used in an asphalt emulsion, a catalyst for urethane, a chelating agent, a material for surfactants, a mining flotation agent, a material for fiber softeners and the like. The present invention also relates to an asphalt emulsion composition which is obtained by using the above-mentioned polyamine.
Heretofore, aliphatic amines, which have a straight-chain alkyl group having 12 to 22 carbon atoms, have been used in an emulsifier or the like for the production of an asphalt emulsion. However, since these amines are solids or pastes at normal temperature, the handling of these amines was not easy. Despite efforts, which have been made traditionally in order to liquefy these compounds, the following problems still remain.
For example, a significant sacrifice of surface activity is associated with the amines obtained by a process described in U.S. Pat. No. 2,930,701 comprising oxyalkylating an alkylamine or an alkylpropylenediamine, or by a process described in U.S. Pat No. 4,561,900 comprising methylating a secondary nitrogen. That is, when these amines are used, the adding amount thereof needs to be larger than that of the solid amine as a material thereof, or alternatively, when these amines are used for the production of an emulsion, a larger amount of mechanical energy is required.
Meanwhile, when a road is paved with an asphalt emulsion, in order to open the road after paving operation thereof quickly to traffic, a method such as slurry seal or micro-surfacing is adopted. In this method, an asphalt emulsion, aggregates and water are loaded in a vehicle by a special mechanism which prevents their mutual contact. The asphalt emulsion, aggregates and water are mixed by a mixer while the vehicle moves and the mixture is spread on a road. In this method, when the asphalt emulsion, aggregates and water be mixed, it is desired that the vehicle runs and puts (or moves) easily on the mixture. Namely, the asphalt emulsion, aggregates and water should be mixed well and the mixture needfully has a sufficient fluidity (being as xe2x80x9cmiscibility of aggregatesxe2x80x9d). Further when the mixture is spread on a road, the demulsification desirably takes place as soon as possible so that the mixture sets (being as xe2x80x9cquick hardenabilityxe2x80x9d). A mixture, which sets within one hour after the spreading thereof so that the pavement is open to traffic, is described as having a quick setting property. Since the setting time significantly varies depending on the types of aggregates and temperatures, it is desired that the setting rate be controllable so that the mixture can be used under various conditions.
In order to meet the above-mentioned points and required performances, a variety of emulsifiers for asphalt and cationic asphalt emulsion compositions have been proposed.
For example, CA-A 953452 discloses a cationic asphalt emulsion in which a quaternary ammonium salt is used as an emulsifier, and U.S. Pat. No. 5,242,492 describes a reaction product made from a fatty acid having 20 or more carbon atoms with a polyamine. However, none of these techniques satisfy the above-mentioned requirements.
Accordingly, one objective of the present invention is to provide an amine which has a surface activity not inferior to that of an amine based on a solid tallow and an excellent workability and which is suited for use in the emulsification of asphalt or the like. Another objective of the present invention is to provide an asphalt emulsion composition which is obtained by using the amine and which has a quick setting property.
The present inventors found that a specific polyamine is in a liquid state at normal temperature and the ability of the specific polyamine to emulsify asphalt is not reduced unlike the case of conventional liquid amines. In addition, they found that an asphalt emulsion composition containing a water-soluble salt of the specific polyamine has an excellent quick setting property; that is to say, the asphalt emulsion composition is excellent in the miscibility of aggregates; the setting time after paving operation can be controlled by the amounts added of fillers, such as cement, slaked lime and the like, and that of water; and the use of this emulsion composition makes it possible to open the road to traffic when one hour elapses after the paving operation under a wide range of conditions.
Accordingly, the present invention provides a polyamine represented by the formula (1) (hereinafter referred to as polyamine (1)), a process for producing the polyamine, use of an amine composed of the polyamine in an asphalt emulsion and an asphalt emulsion composition containing a salt of the amine preferably being water-soluble; 
wherein R is a straight or branched hydrocarbon group having 8 to 22 carbon atoms; x is a number of 1 to 5; and each of y and z is a number of 0 to 5 with the proviso that both of y and z are not 0 at the same time, or a salt thereof.
The invention provides a salt of a polyamine for use in an asphalt emulsion, said amine being obtained by carrying out the cyanoethylation of a compound represented by the formula (2) by reacting 0.2 to 3 moles of acrylonitrile with 1 mole of the compound or carrying out the cyanoethylation of a compound represented by the formula (3) by reacting 1.4 to (m+2) moles of acrylonitrile with 1 mole of the compound; and hydrogenating the cyanoethylation product.
The invention provides an asphalt emulsion composition containing a salt of the polyamine as above described and then an asphalt emulsion comprising asphalt, water and a salt of the polyamine.
The invention provides a method of emulsifying asphalt with a salt of the polyamine. Asphalt may be emulsified with the polyamine and an acid, preferably the polyamine being used in an equivalent or more to the acid.
The invention provides use of a salt of the polyamine as an emulsifier for asphalt.
In the polyamine (1) of the present invention, preferably R has 10 to 20 carbon atoms from the standpoint of emulsifiability and preferably R has 8 to 18 carbon atoms from the standpoint of being a liquid at normal temperature. From these standpoints, most preferably R has 10 to 18 carbon atoms. Besides, the hydrocarbon group may be made up of a mixture of hydrocarbon groups. X is preferably 1 to 2, and most preferably 1. The sum of y and z is preferably 1 to 4, and most preferably 1 to 3.
Examples of the polyamine (1) include the following compounds. Among them, from the standpoint of emulsifiability, preferable examples are (b), (c), (d), (h) and (i), and most preferable examples are (b), (c) and (d). 
The polyamine (1) is obtained by carrying out the cyanoethylation of a compound represented by the formula (2) (hereinafter referred to as compound (2)) or a compound represented by the formula (3) (hereinafter referred to as compound (3)) by reacting acrylonitrile therewith and thereafter hydrogenating the cyanoethylation product; 
wherein R is as defined above; and m is a number of 1 to 3.
Specific examples of the compound (2) include N-myristyl-N-aminopropylpropylenediamine, N-stearyl-N-aminopropylpropylenediamine, N-tallow alkyl-N-aminopropylpropylenediamine and the like.
In the compound (3), m is 1 to 3 and is preferably 1 to 2 from the standpoint of emulsifiability. Besides, the group having m may be made up of a mixture of groups. Specific examples of the compound (3) include myristylpropylenediamine, stearylpropylenediamine, tallow alkylpropylenediamine, palm kernel oil alkylpropylenediamine, tallow alkyldipropylenetriamine, tallow alkyltripropylenetetramine and the like.
When the compound (2) is reacted with acrylonitrile, it is preferable that 0.2 to 3 moles of acrylonitrile be reacted per mole of the compound (2). Meanwhile, when the compound (3) is reacted with acrylonitrile, it is preferable that 1.4 to (m+3) moles of acrylonitrile be reacted per mole of the compound (3).
In the hydrogenating reaction of cyanoethylation product, the reaction temperature is preferable to be 100 to 160xc2x0 C. from the standpoint of preventing by-product as small as possible.
Although the polyamine (1) is suited for use in an asphalt emulsion, a catalyst for urethane, a chelating agent, a material for surfactants, a mining flotation agent, a material for fiber softeners and the like, most preferably the polyamine (1) is used for an asphalt emulsion. When the amine (1) is used for an asphalt emulsion, the amine is preferably a reaction product obtained by a process comprising carrying out the cyanoethylation of a compound (2) by reacting 0.2 to 3 moles, more preferably 0.5 to 1.5 moles, of acrylonitrile with 1 mole thereof and hydrogenating the cyanoethylation product or alternatively by a process comprising carrying out the cyanoethylation of a compound (3) by reacting 1.4 to (m+2) moles, more preferably 1.8 to (m+2) moles, further preferably 2.1 to (m+2) moles from the stand point of liquefiability, of acrylonitrile with 1 mole thereof and hydrogenating the cyanoethylation product. When an alkylpropylenediamine, whose m is 1 in the formula (3), such as myristylpropylenediamine, stearylpropylenediamine, tallow alkylpropylenediamine or the like is used, the reaction molar number of the acrylonitrile for cyanoethylation is preferably in the range of from 1.4 to 3.0 from the standpoint of liquefiability of the amine to be obtained. Likewise, when a compound (3), whose m is 2, is used, the molar number of the acrylonitrile is preferably in the range of from 1.4 to 4.0. And, when a compound (3), whose m is 3, is used, the reaction molar number of the acrylonitrile is preferably in the range of from 1.4 to 5.0.
From the standpoint of being a liquid at 20xc2x0 C. and presenting an excellent workability, the solidification temperature of the polyamine (1) is preferably 20xc2x0 C. or below. The solidification temperature referred herein is measured in accordance with JIS K-2269.
When the polyamine (1) is used in an asphalt emulsion, the polyamine (1) is used in the state of an aqueous solution of a water-soluble salt prepared from the polyamine (1) and a inorganic or organic acid.
Examples of the inorganic or organic acid to be used for the preparation of the water-soluble salt include hydrochloric acid, phosphoric acid, sulfuric acid, nitric acid, acetic acid and glycolic acid. Among them, hydrochloric acid and phosphoric acid are preferred. A preferable pH value of the aqueous solution of a water-soluble salt of the amine varies depending on the kinds of acid to be used. The pH value is preferably 7.0 or below from the standpoint of emulsifiability and emulsion stability. On the other hand, the pH value is preferably 1.0 or above from the standpoint of corrosion prevention of emulsifying machines, storage containers and the like, and also from the standpoint of costs associated with the use of a large amount of acids. More specifically, the pH value is preferably in the range of from 1.5 to 3.5 in the case where hydrochloric acid is used, the pH value is preferably in the range of from 1.5 to 4.0 in case where phosphoric acid is used, and the pH value is preferably in the range of from 4.0 to 7.0 in the case where acetic acid is used.
From the standpoint of emulsifiability and emulsion stability, the content of the water soluble salt of the polyamine (1) in the asphalt emulsion composition of the present invention is preferably 0.05 to 5.0%, more preferably 0.1 to 3.0% and most preferably 0.2 to 2.0% by weight based on the total weight of the asphalt emulsion composition. Besides, a preferable pH value of the asphalt emulsion is 1 to 7.
The asphalt emulsion composition of the present invention can be prepared by passing a water-soluble salt of the polyamine (1) and asphalt at the same time through an emulsifying machine such as a colloid mill. When the asphalt emulsion composition is prepared, the temperature of the asphalt is preferably 110 to 170xc2x0 C. and the temperature of the water-soluble salt of the amine is preferably 30 to 60xc2x0 C.
The asphalt for use can be one ordinarily used for the paving of a road. Examples of the asphalt include straight asphalt, semi-blown asphalt, blown asphalt, polymer-modified asphalt, tar, coal tar and the like.
From the standpoint of better stability of the emulsion composition, the content of the asphalt in the asphalt emulsion composition is preferably 40% by weight or more based on the total weight of the asphalt emulsion composition. On the other hand, from the standpoint of better workability due to the viscosity of the emulsion composition which is not excessively high, the content of the asphalt in the asphalt emulsion composition is preferably 75% or less, more preferably 50 to 70% and most preferably 55 to 65% by weight based on the total weight of the asphalt emulsion composition.
In order to impart a high-level of durability to a road, the asphalt emulsion composition of the present invention preferably contains a polymer or latex for modification of asphalt.
Examples of the polymer for modification of asphalt include synthetic rubbers such as a styrene-butadiene rubber, a styrene-butadiene-styrene rubber, a chloroprene rubber and the like; thermoplastic resins such as an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer and the like; and natural rubbers. Examples of the latex include a styrene-butadiene latex, a chloroprene latex, a neoprene latex and the like. The contents thereof are preferably 1 to 20%, and more preferably 3 to 10% by weight in the composition.
The methods, whereby a polymer or latex for modification of asphalt is incorporated into the asphalt composition of the present invention, include a method wherein asphalt modified with the polymer is used in the preparation of the emulsion composition; and a method wherein the latex is added into the water-soluble salt of the amine for use as an emulsifier, or wherein the latex is added into the emulsion composition. The latex may be added in so far as the addition of the latex does not impair the stability, emulsion stability, miscibility of aggregates at the time of paving operation, and the setting property after paving operation of the asphalt emulsion. Since the use of the latex modifies the asphalt remaining after paving operation as a result of the evaporation of water from the asphalt emulsion composition, the durability of road is remarkably improved.
Further, in order to improve storage stability and workability of the asphalt emulsion composition, additives or emulsification aids may be added to the asphalt emulsion composition. Examples of the additives or emulsification aids include alkylamines and alkylpolyamines; aliphatic amidoamines; alkylimidazolines; quaternary salts; nonionic surfactants such as a polyoxyalkylenealkylphenol; amphoteric surfactants such as alkylbetaine; higher fatty acids; higher alcohols; and inorganic salts such as calcium chloride, sodium chloride and potassium chloride. Further, the asphalt emulsion may contain a water-soluble polymer such as carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol or the like in order to improve storage stability and viscosity. Still further, the asphalt emulsion may contain a polyphenol compound such as tannin or the like in order to improve the adhesion between the aggregates and the asphalt. These additives and emulsification aids may be added to the asphalt emulsion in so far as the addition does not impair the stability, emulsion stability, miscibility of aggregates at the time of paving operation, and the setting property after paving operation of the asphalt emulsion.
Since the asphalt emulsion composition prepared as described above is excellent in miscibility with aggregates and in quick setting property, the asphalt emulsion composition as a quick setting asphalt is suited for use in a method such as slurry seal or micro-surfacing and for use in the repair of the sinking or cracking of road surface. The above-mentioned method comprises a step of mixing aggregates; water; a filler such as cement, slaked lime or the like; and an additive, in a vehicle, and another step of spreading the mixture on a road.
The change in content of the polyamine (1) in the asphalt emulsion composition of the present invention makes it possible to adjust physical properties such as miscibility of aggregates and setting property. Therefore, the asphalt emulsion composition is compatible with a wide range of aggregates. As is experienced in actual paving operation, even if the same aggregates are used, changes in external conditions such as temperature and in the particle size distribution of aggregates cause the time required for the mixing of asphalt emulsion composition with aggregates or the setting property after paving operation to vary. However, according to the present invention, time required for the mixing of asphalt emulsion composition with aggregates or setting property after paving operation can be easily adjusted to the requirements by slightly adjusting the amount of water to be added, the amount of cement or the like. As a result, the slurry seal or micro-surfacing operation can be drastically facilitated because the slurry seal or micro-surfacing operation can be exempted from prior minute adjustment of formulation and skill hitherto required.
FIG. 1 is a 13C-NMR spectrum of the stearyltetramine obtained in following Synthesis example 1.
FIG. 2 is a 13C-NMR spectrum of the tallow alkyltetramine obtained in following Synthesis example 2.